1. Field of the Invention
The present invention relates to external fire escape ladders for high-rise buildings and particularly to a series of ladders between the balconies of each floor, such that the occupants of the burning building can escape simultaneously descending from balcony to balcony, and then to ground level.
2. Description of Prior Art
It is well known that a method of escape from a burning building can be accomplished by means of a system of ladders attached to the exterior walls of a building. In the latter part of this century, with advanced methods of construction, buildings are being built higher and higher. In addition, the trend has been to make interior fireescape stairwells. However, if the fire is from within the building, these inner stairwells become filled with smoke or are not locatable by the building's occupants.
Exterior ladders have been unsightly, and they allow entry to the building from the outside and ground levels. Also, the users of external fire escape ladders are in constant peril of falling because of the difficulty of using the ladders.
One improvement to the fire-escape ladders, documented by the U.S. Pat. No. 3,117,651 to B. L. Singer, et al., on Jan. 14, 1964, and U.S. Pat. No. 1,460,479 to A. S. Dixon on July 3, 1923, is the collapsable ladder which limits access to the upper floors. These ladders when collapsed create a more aesthetic appearance and allow unobstructed views from the balcony. Mr. Dixon's patent claims a rigid ladder to reach the top of the balcony. However, his patent is limited to second floor landings and there is considerable difficulty and peril in moving one's person from the rigid ladder to the folding ladder 1, while "clinging" to the same folding ladder and crossing over the rail at the same time.
In Mr. Singer's invention, access to the collapsable ladder is by means of an opening gate in the balcony rail, which in non-emergency periods could be dangerous.
Safety belts have been suggested as in U.S. Pat. No. 303,638 to A. H. Hall on Aug. 19, 1884. Mr. Hall's belts are used by the operator of the system FIG. 5, and a second belt in his FIG. 7 is used to lower persons to the ground using Rail C, neither of these belts cooperate with the ladder itself.
Other patents describing the closest subject matter provide for a number of more or less complicated features that fail to solve the problem in an efficient and economical way. None of these patents suggest the novel features of the present invention.